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6 BioScience r XXXX XXXX / Vol. XX No. X
species’ ranges shift. This blended approach is a bet-hedging
strategy for a changing climate, because it identifies linkages
that should work under a wide range of future climates.
If adopted, this linkage design would be the most
geographically extensive attempt thus far to use the conservation of corridors as a climate adaptation strategy.
Therefore, the DRECP has the potential to robustly support the adaptation of desert ecosystems over a large area
while promoting alternative energy. Key public agencies—
including the seven affected counties that are to use the
DRECP to amend their land-use plans—have the appropriate legal authority to shape factors that influence ecosystem
conditions and adaptive capacity.
The DRECP recently released a draft report and environmental impact statement to comply with the National
Environmental Policy Act and the California Environmental
Quality Act and opened a public comment period (CEC 2014).
The draft identifies a preferred alternative that prioritizes large
habitat blocks and linkage areas for 37 covered species and 31
natural communities, as well as approximately 8,200 km2 for
solar, wind, and geothermal development (to produce approximately 20 gigawatts of renewable energy). The plan and a
preferred alternative are likely to be modified in response to
public comment, and their implementation will take years and
will involve decisions by many different entities.
Simple procedures are available that the DRECP and the
plan implementers could use to quantitatively estimate the
loss of connectivity associated with each energy-siting alternative under consideration (Rudnick et al. 2012). Combining
these results with estimates of the amount of energy produced or transmitted under each alternative would describe
a trade-off curve that could inform the choice among
alternatives and identify compromises which meet energy
needs while conserving a well-connected landscape that
supports species range shifts and ecosystem transitions.
Complementary analyses, using other tools (e.g., Mojaveset;
Davis et al. 2015), could estimate how siting alternatives alter
the conservation value of the landscape through the loss of
habitat to energy development.
The DRECP is likely to result in the rapid implementation of long-lived and expensive energy infrastructure over
a significant proportion of California’s desert ecosystems.
Surprises are inevitable, even if the DRECP relies on the
best available data and models. Monitoring in an adaptive
management framework can help address uncertainty, but
the rapid infrastructure development makes it unlikely that
monitoring will produce strong inferences in time to mitigate unanticipated effects of the installations built within the
next decade. This argues for a precautionary strategy that
builds a significant margin for error into the connectivity
plans and projections of climate change effects.
Case study 2: A choice among alternative futures for
Suisun Marsh
Suisun Marsh is the largest tidal marsh on the West Coast,
covering approximately 400 km2 in the middle of the San
http://bioscience.oxfordjournals.org
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the region. The 4000–8000 km2 of energy projects that are
eventually likely to be built could have substantial ecological impacts. Large installations—and the associated roads,
transmission lines, and human workforce—could significantly fragment the landscape, thereby limiting opportunities for species range shifts; degrading desert habitats;
and undermining the ecosystem’s conservation benefits,
adaptive capacity, and transitions under climate change.
Numerous endangered species could be affected, such as the
desert tortoise (Gopherus agassizii), the desert bighorn sheep
(Ovis canadensis nelsoni), and the Mohave ground squirrel
(Xerospermophilus mohavensis).
To reduce such collateral ecological impacts and achieve
California’s dual policy goals of wildlife conservation and
renewable energy development, a collaborative effort was
initiated in 2008 to create the Desert Renewable Energy
Conservation Plan (DRECP) by the California Energy
Commission, the California Department of Fish and Wildlife
(CDFW), the US Bureau of Land Management (USBLM),
and the US Fish and Wildlife Service (USFWS). If approved,
the DRECP will serve as a general conservation plan, covering approximately 22,300 km2 of nonfederal lands to streamline the development of habitat conservation plans under the
US Endangered Species Act; a USBLM land-use-planning
amendment covering approximately 40,000 km2 of federal
lands; and a natural community conservation plan under the
California Natural Community Conservation Plan Act for
reconciling economic development and conservation across
the entire planning region.
Although measures to benefit covered species (i.e., those
listed or likely to be listed as threatened or endangered under
federal or state law) are the DRECP’s primary focus, it is also
intended to support the region’s biodiversity and ecosystems
as they shift under climate change. The USBLM took a promising step in this direction in 2010, when it commissioned a
regional plan designed to support connectivity under current
and future climatic conditions (figure 2b; Penrod et al. 2012).
The plan builds on the region’s existing large protected areas
and includes 22 broad, multistranded linkages. Each linkage
includes high climate diversity, supports large populations
(and, therefore, large evolutionary potential and demographic resilience) of most species, and has a low edge-toarea ratio (reducing exposure to noise, light, pollutants, and
other threats originating in developed areas).
The linkages combine corridors for focal species under
today’s climatic conditions with corridors designed to support connectivity and viable metapopulations of most species as the climate changes (figure 2b; Penrod et al. 2012).
The latter are defined by enduring features of the landscape
(Beier and Brost 2010). This approach avoids the significant
uncertainties that would arise in modeling suitable climate
space for every focal species over the next 50 to 100 years
(Davis et al. 2015) and in joining all those corridors into
a coherent design. The combined network links today’s
habitats with what should be suitable habitats in the future,
thereby providing live-in and move-through habitat as